When I get out of the shower, I'm sweating within minutes—even in an air-conditioned room. Why do I sweat so much?

Dr. Oz says there are at least three things that could be causing so much sweat. "You have to make sure your thyroid gland is normal," he says. "If your thyroid is working overtime, it will make you sweat a little bit." Dr. Oz says that thyroid issues are the most common hormonal problem in America. If you are feeling a bit off, your doctor can check it with a simple blood test.

Another cause of excessive sweat could be the presence of toxins—such as mercury—in your body. That sweat is your body's way of ridding itself of the toxins.

The third possibility? High blood pressure. If you do have high blood pressure, Dr. Oz says the danger lies in more than what an antiperspirant can cure.

While optimal blood pressure is 115 over 75, Dr. Oz says the average American's blood pressure is 130 over 85. "And what happens to the average American? We die of a heart attack," Dr. Oz says. "You don't want to be average, you want to be optimal. You want to do the right thing.

"Do you know why African-Americans have high blood pressure?" Dr. Oz asks Oprah.

"The reason why African-Americans have higher blood pressure, Dr. Oz, is because during the Middle Passage [when Africans were taken as slaves to America], the African-Americans who survived were those who could hold more salt into their body," Oprah says. "And those who didn't survive were the ones who couldn't hold more salt into their body."

"I'm off the show, you don't need me anymore—that's perfect!" Dr. Oz says.